Flurbiprofen which is one kind of nonsteroidal anti-inflammatory drugs (NSAIDs) is a drug having wide applicability to chronic rheumatism, osteoarthritis deformans, omarthritis, lumbago, tendovaginitis, muscle pain and the like, and is administered orally in the dosage forms of tablet, granules and the like, or transdermally in the dosage forms of ointment, plasteres and the like.
Preparations for oral administration disadvantageously cause appearance of side effect such as gastrointestinal damage specifically observed in NSAIDs, and decrease in drug efficacy because the drug having absorbed in the body is metabolized and decomposed in early stage by liver.
Contrarily, preparations for transdermal administration do not cause side effect and drug metabolism in liver as is the case of oral preparations, and enable constant supply of drug into a body in continuous manner for a long term.
In view of the above, with regard to flurbiprofen, transdermally absorbable preparations that will not pass along a gastrointestinal tract, liver and the like attract the attention, and among such preparations, plasteres for external use attract attentions for their excellent continuity of drug release, and easiness of handling, and several attempts have been made heretofore.
For example, Patent Document 1 (Japanese Patent Laid-Open Publication No. Sho 56-154413) and Patent document 2 (Japanese Patent Laid-Open Publication No. Hei 11-199515) disclose cataplasm using a water-soluble polymer containing flurbiprofen as an active ingredient. However, since such cataplasm contains a large amount of water, flurbiprofen, which is an active ingredient, is difficult to be blended in a high concentration, and transdermal absorption of drug is poor, and it cannot be mentioned that sufficient drug efficacy is obtained.
For compensating such drawbacks of cataplasm, several reports of plasteres using rubber-based adhesives have been made. For example, Patent Document 3 (Japanese Patent Laid-Open Publication No. Hei 8-319234) reports a plaster, which contains an adhesive, made up of a rubber component, a tackifying resin and a softener, and flurbiprofen blended therein. However, the adhesive constituting the plaster of Patent Document 3 little contains a component that dissolves flurbiprofen, so that flurbiprofen is dispersed in crystal forms in the preparation. Therefore, it is conceivable that drug releasability would be very poor.
Patent Document 4 (WO 93/04677), which uses other rubber-based adhesive, discloses a tape-type preparation containing 1-menthol as a resolvent for flurbiprofen. However, volatile 1-menthol vaporizes during storage, and crystals of flurbiprofen, which is a principal agent, may be generated.
Furthermore, Patent Document 5 (Japanese Patent Laid-Open Publication No. Hei 7-309749) reports a rubber-based adhesive using lactic acid ester as a resolvent for flurbiprofen, however, such a resolvent may leave residual adhesive on skin due to destruction of cohesive power of adhesive when the preparation is detached, and may give skin irritation.    Patent Document 1: Japanese Patent Laid-Open Publication No. Sho 56-154413    Patent Document 2: Japanese Patent Laid-Open Publication No. Hei 11-199515    Patent Document 3: Japanese Patent Laid-Open Publication No. Hei 8-319234    Patent Document 4: WO 93/04677    Patent document 5: Japanese Patent Laid-Open Publication No. Hei 7-309749